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1. Inspect all lead dress to make certain that
leads are not pinched orthat hardware isnot
lodged between the chassis and other metal
parts inthe unit.
2.Be sure that any protective devices such as
nonmetallic control knobs, insulating fish-
papers, cabinet backs, adjustment and
compartment covers or shields, isolation
resistor -capacity networks, mechanical
insulators, etc. Which were removed for the
servicing are properly re-installed.
Before returning the unit tothe user ,perform the following safety checks :
3. Be sure that no shock hazard exists ;check for leakage
current using Simpson Model 229 Leakage Tester ,standard
equipment item No. 21641, RCA Model WT540A or use
alternate method as follows :Plug the power cord directly
Into a120 volt AC receptacle (do not use an Isolation
Transformer for this test). Using two clip leads, connect a
1500 ohms, 10watt Resistor paralleled by a0.15uF capacitor ,inseries with allexposed metal cabinet parts and aknown earth ground, such
as awater pipe orconduit. Use aVTVM orVOM with 1000 ohms per volt, orhigher sensitivity tomeasure the AC voltage drop across the
resistor .(See diagram) Move the resistor connection to each exposed metal part having areturn path to the chassis (antenna, metal,
cabinet, screw heads, knobs and control shafts, escutcheon, etc.) and measure the AC voltage drop across the resistor .(This test should be
performed with the 0.35 volt RMS ormore isexcessive and indicates apotential shock hazard which must be corrected before returning the
unit tothe owner .
HK3480 harman/kardon
